Method for reconditioning the extruding face of spinnerettes



Aug. 25, 1953 w. MARTIN ETAL 2,549,670

METHOD FOR RECONDITIONING THE EXTRUDING FACE OF SPINNERETTES Filed July 28, 1951 /24 6 \/Z K Z0 55 53k 7'6 M m 7 INVEJNTOR.

i atenteci Aug.

v UNITED STATES '7 Claims.

,The present invention relates to a method for reconditioning the extruding face of a spinnerette which allows the exit openings of the nozzles of the spinnerette to be protected against damage during the reconditioning. More particularly, the present invention relates to a method for polishing the extruding face of the spinnerette.

The polishing of the extruding face of a spinnerette has always met with difficulties because the extremely fine exit openings of the nozzles thereof which have a diameter amounting at times only to 50 micron, lost the sharp and smooth edges thereof during the grinding or polishing operations. This phenomenon is to be explained by the fact that during the grinding or polishing operations parts of the extruding face of the spinnerette are removed so that the metal particles situated at the edges of the nozzles are torn from the structure of the edge so that the exit opening loses the sharp and smooth edge thereof. On the other hand, a sharp and smooth edge is indispensable for extruding a filament through the spinnerette.

In order to overcome this drawback, a method was applied hitherto in which the exit openings of the nozzles were provided with a filling material which was chemically removed after the polishin operation. This filling material had to have certain properties in order to secure the desired effect. During bringing in the filler, the same had to be in condition of a liquid having a low viscosity so that it could penetrate into each nozzle. However, the melting points of the filling material were often too high so that the alloy structure of the spinnerette was impaired. In consequence thereof, it has been suggested to fill the openings of the nozzle by a low-melting synthetic resin, so that the material of the spinnerette can withstand the temperature of the molten resin.

Experience, however, has shown that this method is not applicable to the grinding and polishing of the extruding face of spinnerettes consisting of hard metal because the filling materials hitherto used are too soft.

It is an object of the present invention to overcome this drawback.

It is another object of the present invention to provide a filling material which conserves the natural hardness thereof.

A method according to the invention for reconditioning, such as grinding or polishing the extruding face of a spinnerette comprises the steps of placing a pin into the nozzle of the spinnerette so as to close the exit opening of the nozzle, reconditioning the extruding face of the spinnerette while the exit opening of the nozzle is closed by the pin, and removing the pin from the nozzle of the spinnerette after the extruding face thereof has been reconditioned, whereby the exit opening of the nozzle is protected against PATENT OFFICE ivliirrioii FOR RECONDITIGINING T'H'E EX- TR-UDING FACE OF SPINNERETTES Wilhelm Martin and Wilhelm Heynen, Grebben, Kreis Heinsberg, Germany, assignors to Firma Vereinigte Glanzstoif-Fabriken A. G., Wu:- pertal (Elberfeld), Germany Application July 28, 1951, Serial No. 239,078 In Germany July 28, 1950 damage during the reconditioning of the extruding face of the spinnerette.

Preferably, the spinnerette consists of hard metal and the pin consists of the same metal as a spinnerette.

Preferably, the pin is pushed after the reconditioning of the extruding face of the spinnerette toward the extruding face through the exit opening of the nozzle.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Fig. l is a perspective view of a spinnerette provided with nozzles thereof before reconditioning, the nozzles of the spinnerette being shown at an enlarged scale; and

Fig. 2 is a cross-section of part of the spinnerette showing two nozzles obstructed by pins and one nozzle free with the pin taken out of the same.

Referring now to the drawings, the spinnerette i0 consisting of hard metal is provided with a plurality of nozzles l2 having exit openings l4 through which the spinning solution escapes. The exit openings I l are arranged flush with the extruding face if: of the spinnerette H! which has to be reconditioned, by mechanically treating for instance, grinding and polishing the extruding surface i6 from time to time so as to smoothen the same. In order to protect the exit openings M of the nozzles 12, pins l8 consisting of the same material as the spinnerette are placed in the nozzles l2 so that the front ends 20 of the same at first protrude somewhat beyond the exit opening 14' and the extruding face it as shown in slightly exaggerated manner in Fig. 1, whereas the rear ends 22 of the pins preferably project by a distance beyond the rear face 2 of the nozzle l2.

After the extruding face l6 of the spinnerette has been ground and polished, the front ends of the pins iii are flush with the extruding face l6 so that the edges of the exit openings M are not damaged by the grinding and polishing operation. After the grinding and polishing operation has been performed, the pins l8 are pushed out of the nozzles l2 in the direction of the arrow 26 shown in Fig. 2 toward the extruding face 16. The pushingof the pins I8 is preferably performed mechanically'from the rear ends 22 thereof.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other'types of methods for reconditioning the extruding face of a spinnerette, differing from the types described above.

3 While the invention has been illustrated and described as embodied in a method for reconditioning the extruding face of a spinnerette allowthe exit opening ofthe nozzle; polishing the exing the exit openings of the nozzl s thereof tobe protected against damage, it is ri'pt intended to be limited to the details shown, since various 'm0difications and structural changes .may: be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will'so fully reveal the gist of the presentinvention that others can by applying current knowledgereadilyadapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and'are inarranged flush with the extruding face of the spinnerette, comprising the steps of placing a pin into the nozzle of the spinnerette so as to close trudingtace ofjthe spinnerette so as to smoothen thesa'me while the exit opening of the nozzle is closed ,by saidpin; and pushin said pin toward the extruding'..face:of the spinnerette through the exit opening of the nozzle after the extruding face of the spinnerette has been polished, whereby the exit ;opening of the nozzle is protected against damage :during the polishing of the extruding tended to be comprehended within the meaning and range of equivalence of the following claims. What is claimed as new and desired to be secured by Letters Patent is: I 1.- A method for reconditioning a spinnerette having a nozzle provided with an exitopening arranged flush with the extruding face of the spinnerette, comprising the steps of placing a pin intothe nozzle of the spinnerette so as to close the exit opening of the nozzle; mechanically treating the extruding face of the spinnerette so as to smoothen the same while the exit opening ofthe'nozzle is 'cl'osedby-said pin; and pushing said pin toward the extruding face of the spinnerette through the exit opening of the nozzle afte'rthe' extrudin'gface of the spinnerette has been mechanically treated, whereby the exit openingof thenozzle is protected against damage during the mechanicallytreating of the extruding face of the spinnerette.

. 25A method, for, recond tioning a sp t consisting of metal ,andhaving a nozzle provided with an exit opening arranged flush with the extruding face of thespinnerette, comprising the 'stepslof placing a pin into the nozzle ofthe spinnerette so, as to close the exit opening of the noz- 218., said pin consisting of the same metal as the spinnerette; mechanically treating the extruding face of-the spinnerette so as to smoothen the same whilethe exit opening of the nozzle is closed by saidpin; and pushing said pin toward the extrudin face of the spinnerette through the exit opening of the nozzle after the extruding face of the pinnerette has been mechanically treated, whereby the exit opening of the nozzle is protected against damage during the mechanical treatment .ofthevextrudin'g face of the spinnerette. I

3. A method for reconditioning a spinnerette consisting of metal andhaving a nozzle provided with an exit opening arranged flush with the extruding face of the spinnerette, comprising the steps of placing a pin into the nozzle of-the spinnerette so as to .close the exit openin of the nozzle, said pin-consisting of the same metal as the spinnerette; grindin the extruding face of the spinnerette so'as t9 smoothen the same while the-exit opening of the nozzle *isclosed by said pinata pushing said pin toward the extruding face of 'the spinnerette through the exit opening of the nozzle after the-extruding face of the spinnerette has been ground, whereby the exit opening of the nozzle is protected against damage during the. grindin of the extruding face of the spinnerette. V

4. A method forrec'onditioning a spinnerette having a nozzle provided with an exit opening face of the spinnerette.

'5 A method for reconditioning a spinnerette consisting of metal andfhaving a nozzle provided with an .exit openingarranged flush with theextruding face of the spinnerette, comprising the steps of placing a pin into the nozzle of the spinnerette so as to close the exit opening of the nozzle, said piniconsisting of the same metal as the spinnerette; polishing the extruding face of the spinnerette so as to smoothen the same while the exit opening of the nozzle is closed by said pin; and pushing said pin toward the extruding face of the spinnerette through the exit opening of the nozzle after the extrudingface of the spinnerette has'been poli s'hedi whereby the exit opening of the" nozzle is protected against damage during thefpolishing' ofthe extruding face of the spinnerette 1 g 6. A method'for' reconditioning alspin'nerette consisting .of 'metal and having a plurality of nozzles eaehprovided withan exit opening arranged flush with the "extruding face of the spinnerette, comprising the steps'of placing a plurality of pins into the nozzles of the spinnerette, respectively; so as to close the exit openings of the nozzles, said pins consisting of thesame metal as the spinnerette; mechanically treating the extruding face of the spinnerette so as to smoothen the same while 'the'exit openings of the nozzles are closed by said pins; and pushing said pins toward the extruding face of the spinnerette through the :exit openings of the nozzle after. the extruding face ofthespinnerette has been me ohanicallyfjtreated, whereby the exit openings of the nozzles are protected against damage during the mechanical treatment ofthe extruding face e p-merge T A e fh or re o ti n n a ne e te or the extruding face of t hec spinnerette.

M I LHE M H XNE References Citedin-the file of this patent NITED ,S'RA' TES, PA EN Number me v Bate 1 ,654,936 Jones Jan-,3, 1928. 2,115,402 I Spaanbroel; 'Apr. 2.6, 19-38 2,159,291 ivi i 1\4[a 23 1939 2,570,765 e l; t- 

